<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    .box{
      width: 100px;
      height: 100px;
      border: 50px solid blue;
      /* background-color: red; */
      border-left-color: transparent;
      border-bottom-color: transparent;
      border-right-color: transparent;
      border-top-color: orange;
      box-sizing: border-box;
      /* 旋转 */
      transform: rotate(90deg);  
      /* 修改旋转点 */
      transform-origin:center 30% ;
    }
  </style>
</head>
<body>
  <div class="box"></div>
</body>
</html> 